THURSDAY, June 27 (HealthDay News) -- People who think stress is affecting their health may be setting themselves up for a heart attack, a new study contends.

The researchers found that these people had double the risk of a heart attack compared with people who didn't think stress was harming their health.

"People's perceptions about the impact of stress on their health are likely to be correct," said study author Hermann Nabi, a senior research associate at the Centre for Research in Epidemiology and Population Health at INSERM in Villejuif, France.

"They may need to take actions when they feel that it is the case," he added.

These findings have both clinical and theoretical implications, Nabi said.

"From a clinical perspective, they suggest that complaints of adverse impact of stress on health should not be ignored in clinical settings as they may indicate increased risk of developing coronary heart disease," he said.

From a theoretical perspective, the findings imply that the perceived impact of stress on health is a valid concept that should be considered in future studies aimed at examining the association between stress and health outcomes, Nabi added.

The report was published June 27 in the online edition of the European Heart Journal.

Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, said that "stress and reactions to stressful situations have been associated with increased risk of cardiovascular disease in many studies."

However, few studies have looked at whether an individual's perception of stress is associated with cardiovascular outcomes, he said.

And it's not clear if reducing stress would affect the risk for heart attack, Fonarow said.

"Further studies are needed to determine whether stress reduction or other risk reduction strategies can reduce cardiovascular events in men and women who perceive they are under stress that is adversely impacting their health," he said.

For the study, Nabi's team collected data on more than 7,000 men and women who took part in the Whitehall II study, which has followed London-based civil servants since 1985.

Participants were asked how much they felt that stress or pressure in their lives had affected their health. Based on their answers, they were placed into one of three groups: "not at all," "slightly or moderately," or "a lot or extremely."

Participants were also asked about their levels of stress and other lifestyle factors such as smoking, drinking, diet and physical activity.

The researchers also collected medical information, such as blood pressure, diabetes status and weight, and other data, including marital status, age, sex, ethnicity and socioeconomic status.

Over 18 years of follow-up, there were 352 heart attacks or deaths from heart attack.

After taking all of these factors into account, the investigators found those who said their health was a "lot or extremely" affected by stress had more than double the risk of a heart attack compared with those who said stress had no effect on their health.

After further adjustments for biological, behavioral and other psychological risk factors -- including stress levels and measures of social support -- the risk wasn't as high. But it was still a lot higher (49 percent higher) than among those who said stress didn't affect their health, the researchers noted.

While the study found an association between perceived levels of stress and heart attack, it did not prove cause-and-effect.

Samantha Heller, a senior clinical nutritionist at NYU Langone Medical Center in New York City, offered some tips on dealing with stress.

The stress response is not only a mental reaction to a situation, but a physiological reaction, she explained.

"Acute and chronic stress over time can make us sick. Our perception of how that stress affects our health may be an additional stressor biochemically, psychologically and physiologically, creating a feedback loop that results in increased physical distress and disease," Heller said.

Managing stress does not mean ignoring it, she said. "Working with a qualified mental health professional who specializes in cognitive behavioral therapy can be very helpful. In lieu of that, there are some things you can do on your own."

Take several slow deep breaths periodically throughout the day. Deep breathing can shift the body out of the fight-or-flight response.

Exercise regularly. Cardiovascular exercise teaches the body how to handle the physiological effects of stress. It also helps reduce anxiety and depression.

Eat as healthfully as possible. Chronic or acute stress may trigger the desire to dive into high-calorie comfort foods. However, after an initial flash of relief, you will tend to feel lethargic, fatigued and possibly worse than you did before.

Identify stressful triggers, and create a plan to help you cope.

Instead of stressing about your health, be proactive and find ways to improve it. If you have high blood pressure, learn how to lower the sodium in your diet. Start walking a few days a week to strengthen your heart and help manage weight.